Color developing process



United States Patent Int. Cl. G03c7/30, 5/30 US. Cl. 96--55 4 Claims ABSTRACT OF THE DISCLOSURE Exposed silver halide color photographic elements are developed with a color developer containing p-phenylenediamine or derivative thereof, polyoxyethylene alkylphenyl ether and p-aminophenol or derivative thereof, whereby the color developing speed is promoted, the deficiency in silver bleaching and color contamination are reduced, and the photographic qualities are improved.

The present invention relates generally to an improved color developing process for silver halide color photographic elements and more particularly to a color developing process using polyoxyethylene alkylphenyl ether and p-aminophenol or derivatives thereof to promote the color developing speed, reduce the deficiency in silver bleaching and color contamination, and to improve picture qualities.

Since a conventional color developer containing as a color developing agent p-phenylenediamine or derivatives thereof is low in developing power as compared with a general black and white developer, the pH value of the processing solution must be extremely high or the developing procedure must be conducted for a very long period of time. Accordingly, there have hitherto been employed various color developing accelerators but the use of such conventional color developing accelerators frequently causes at development fogging at the unexposed areas resulting in contaminating the pictures or images and further, if the developing period of time is reduced for preventing the formation of fog, no increase in the color density of the image portions is observed and hence the color developing processing cannot be conducted effectively.

In particular, in a color developing process process using a color developer containing couplers therein, the use of a color developing accelerator frequently causes undesirable color fogging or color contamination.

Further, the presence of the developing accelerator in a bleaching process for developed silver after the color development frequently reduces the oxidation speed of silver, that is, causes the phenomenon of so-called insufficient silver bleaching.

Thus, there are presently very few color development accelerators having excellent properties as aforementioned.

Accordingly, an object of the present invention is to accelerate the color developing speed and also increase the color density.

Another object of the present invention is to improve the silver-bleaching in color photographic processing.

Still another object of the present invention is to reduce or prevent the decontamination or color contamination in color photography.

It has been found that after investigation that by using a color developer containing p-phenylenediamine or derivatives thereof incorporated with a below-stating polyoxyethylene alkylphenyl ether and p-aminophenol or a derivative thereof, the color developing speed can be reice markably increased as well as the silver bleaching improved and hence decontamination or color decontamination reduced to improve the qualities of photographic pictures.

It is known that the use of a polyoxyethlene alkylphenyl ether alone accelerates the developing speed but at the same time results in undesirable contamination or color contamination. Further, some kinds of couplers are present at color development, the use of such a developing acclerator will cause insuflicient silver bleaching. However, if the developing accelerator is used together with p-aminophenol or derivatives thereof in color development, the developing speed is accelerated more effectively, as compared with the case of using the developing acceleration alone, and the abovementioned various faults are reduced.

The polyoxyethylene alky phenyl ether used in the present invention can be represented by the following general formula wherein R and R' are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and n is a number of 5 to 50.

The compounds shown by the above general formula are illustrated as follows:

The suitable amount of the abovementioned polyoxyethylene alkylphenol other is usually from 0.5 to 10 g./

ter. The amount may be less or more than the range it if it is less than 0.5 g./iiter the effect of the addition .ereof will be Weak and it higher than 10 g./liter the feet Will not be increased more and hence the addition too much amount of the compound is unnecessary.

The p-aminophenol derivatives used in this invention 7e N-methylaminophenol sulfate (metol), o,prdiaminoaenol hydrochloride (amidol), and N-benzyl-p-aminonenol. Although the effect may be slightly iess than those 5 the abovementioned derivatives, p-aminophenol may be so used in this invention. In this respect, it must be iderstood that the use of p-aminophenol or the derivaves thereof among various black and white developing gents is important in this invention since the use of :her black and White developing agents together with the aovementioned developing accelerator increases, on the )ntrary, the contamination or color contamination. Furler, if the abovementioned p-aminophenol or the derivaves thereof are added alone in a color developer, a .ack and white development occurs simultaneously with re occurrence of a color development, which results in re reduction of color density and only if the amount lereof is properly selected some extent of the increase color density is observed in a limited range of ex- DSUIC and developing period of time. However, as the Jovementioned polyoxyethylene alkylphenyl ether is resent together with the p-aminophenol derivatives or pninophenol in the color developer, the color density can a remarkably increased without increasing color fogging. A suitable amount of p-aminophenol or the derivaves thereof to be incorporated in the developer is 0.1 to g./liter. The amount may be less or higher than this tnge but if the amount is less than 0.1 g./ liter, the efiect E additon thereof becomes insufiicient and if it is higher tan 1 g./liter the color density tends to decrease on the )ntrary. Two or more kinds of the abovementioned pninophenol and the derivatives thereof may be used in 11S invention.

Thus, by using the abovementioned two compounds ac- )rding to the present invention, said two compounds eing impracticable individually owing to their drawbacks, 1e faults of the two compounds are compensated for by tch other to make possible the practical use thereof as ell as an unexpected remarkable development acceleratlg effect which has never been expected from the inter- :tion of them.

The present invention may generally be applied to color hotographic elements using a color developer containlg p-phenylene-diamine or derivatives thereof, such as egative color photographic films, photographic color apers, photographic color reversal films and the like. 1 particular, the most effective results of this invention an be obtained in the case of conducting this invention JOUt a yellow color developer for photographic color :versal film having technical difficulties in silver bleach- \g and color decontamination.

The following examples illustrate but do not limit the resent invention:

EXAMPLE 1 A test sample which had been prepared by applying a lue-sensitive gelatino silver bromo-iodide emulsion to cellulose acetate film was exposed by means of a :nsitometer and subjected to the following processings:

First developer:

N-methyl-p-aminophenol sulfate g 2.0 Sodium sulfite g 90.0 Hydroquinone g 8.0 Sodium carbonate (monohydrate) g 52.5 Potassium bromide g 5.0 Potassium thiocyanate g Water to make 1 liter.

Color developer:

Sodium sulfite g 5.0 p-Amino-N,Ndiethylaniline sulfite g 2.5 Potassium bromide g 1.0 Potassium iodide (0.1% aq. soln.) ml 5 1 w benzoyi 4 (p toluenesulfonamido)- acetanilide g 1.2

Sodium hydroxide g 2.5 Water to make 1 liter.

Bleaching solution:

Potassium ferricyanide g 100 Potasium bromide g 10 Borax g 2 Boric acid g 1 Water to make 1 liter.

Fixing solution:

Sodium thiosulfate gfl Sodium sulfite g 10 Water to make 1 liter.

The color densities and the silver-bleaching effects were measured in this processing about the cases of using the polyoxyethylene alkylphenyl ether .or the p-aminophenol derivative aione and using both of them, the results of which are shown in Table 1. The color density is shown by the value obtained by measuring the maximum density range of thus processed film using a blue filter light and the silver-bleaching effect is shown by the value of the blackened density (D caused by the remaining silver measured by using a red filter light divided by the color density value (D obtained from measuring by using a blue filter light.

Thus, a yellow color image having a high color density and a high transparency was obtained by using compound (D) and benzylaminophenol together as compared with the cases of using compound (D) or benzylaminophenol individually.

EXAMPLE 2 To a cellulose acetate film were applied a red-sensitive gelatino silver bromo-iodide emulsion, a green-sensitive gelatino silver bromo-iodide emulsion, a yellow filter layer composed of colloidal silver for absorbing blue light, and a blue-sensitive silver bromo-iodide emulsion in this order to provide a multi-layered color photographic film,

which was exposed using a sensitometer and subjected to the following processings:

The compositions of the processing solutions are as follows:

The compositions of the first developer and the second black and white developer are same as the composition of the primary developing solution in Example 1.

Cyan color developer:

Sodium sulfite g 5.0

4-amino-3-methyl-N, N-diethylaniline hydrochloride g 1.5 Sodium carbonate (mono-hydrate) g 15.0 Potassium bromide g 1.0 Potassium iodide (0.1% aq. soln.) ml 2 1,5-dihydroxy-2-6-dibromonaphthalene g 1.2 Sodium hydroxide g 2.0 Water to make 1 liter.

The composition of the yellow developer is same as that of the color developer in Example 1.

Magenta color developer:

The compositions of the bleaching solution and the fixing solution are same as those in Example 1.

The effect of the addition of the compounds of this invention to the yellow color developer in the above processings is shown in Table 2. In the table, the color density (D was measured by a blue filter light. The silver bleaching was measured about the samples exposed to yellow patch. The color contamination (1) shows the ratio of the color density (D obtained by measuring with a green filter light a sample exposed to yellow patch to the color density .(D obtained by measuring it with a blue filter light, that is, the ratio of unnecessary magenta color components in the yellow image and the color contamination (2) shows the ratio of the color density (D obtained by measuring 'with a blue filter light a sample exposed to a magneta patch to the color density (D obtained by measuring it with a green filter light, that is, the ratio of unnecessary yellow components in the magenta color image.

TABLE 2 Silver Color Contamination Addition Compounds Color Bleaching Density Efiect (1) Compound E Metol (DB) (Dn/DB) o/ B) B/ o) EXAMPLE 3 By repeating the procedure as in Example 2 using a standard composition for the yellow developer while in- 5 corporating the compounds of this invention in the cyan color developer, the results of which are shown in Table 3.

TABLE 3 Color Contamination Addition Compound Coupling Density (2) Compound B Am1dol (D n) (D n/Dn) (D RID B) The color density in Table 3 is a value measured by using a red filter light, the color contamination (1) shows the unnecessary yellow components in the cyan color patch and the color bleaching (2) shows the unnecessary cyan color components in yellow patch.

EXAMPLE 4 A gelatino silver bromo-iodide emulsion containing a yellow coupler was applied to a cellulose acetate film to provide a test sample, which was exposed by means of a NSG actionometer and then subjected to the following processmgs:

Color development min. at 24 C-.. 8 Water rinsing sec 30 Primary fixing min 4 Water rinsing min 5 Bleaching min 4 Water rinsing min 5 Secondary fixing min 4 Water rinsing min 5 The compositions of the processing solutions were as follows:

Color developer:

Benzyl alcohol ml 3 Hydroxylamine sulfate g 2 Sodium sulfite g 2 3-methyl-4-amino-N-ethyl-methanesulfonamidoethylaniline sulfate g 1.5 Sodium carbonate (mono-hydrate) g Potassium bromide g 1 Sodium hydroxide g 0.1 60 Water to make 1 liter. Fixing solution (first):

Sodium sulfite g 15 Sodium thiosultate g 150 Acetic acid (28%) -ml.. 48

Boric acid g 7 Potassium alum g 15 Water to make 1 liter.

Bleaching solution:

Potassium bromide g 20 Potassium dichromate g 5 Potassium alum g 40 Sodium acetate g 8 Acetic acid g 57 Water to make 1 liter.

ixing solution (second):

Sodium thiosulfate g 150 Sodium sulfate g 15 Potassium alum g 15 Water to make 1 liter.

TABLE 4 Silver Addition Compound Color Bleaching Density Relative Efiect Color Compound F Metol (D 3) Sensitivity (D R/D B) Fog 0 1. 50 2. l0 0. 15 0. 26 1. 0 0 l. 65 2. 20 0. 20 0.30 0 0. 2 l. 48 2. 10 O. 12 0. 23 1. 0 0.2 1. 69 2. 24 0. 12 0.22

(In the table, the relative sensitivity was shown by the :lative value of the logarithmic exposure amount at the JiIlt Where the density reaches fog +0.2.)

EXAMPLE By repeating the sample procedure as in Example 1 sing .15/liter of methylaminophenol sulfate instead of enzyl aminophenol and 2.0 g./liter of compound (K) stead of compound (D), the following results were btained:

We claim:

1. In color developing process for color photographic silver halide elements, a color developer containing a member selected from the group consisting of p-phenylenediamine and the derivatives thereof is used, the improvement which comprises in said color developer (A) phenyl ether represented by the general formula:

wherein R and R represent a member selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 5 carbon atoms and n is a number of from 5 to 50, and (B) at least one component selected from the group consisting of N-rnethyl-p-aminophenol, o,p-diaminophenol, N-bcnzyl-p-aminophenol and p-aminophe- 1101.

2. The color developing process as in claim 1, wherein the amount of said component (B) to the color developer is 0.1 to 1 g./liter.

3. The color developing process as in claim 1, wherein the amount of said component (A) to the color developing solution is 0.5 to 10 g./ liter.

4. The color developing process as in claim 1, wherein at least one of the R and R groups of component A is an alkyl group.

References Cited UNITED STATES PATENTS 2,531,832 11/1950 Stanton 9666.3 3,158,483 11/1964 Lowe et al. 96-66.3 3,300,305 1/1967 Pesch et a1. 9622 J. TRAVIS BROWN, Primary Examiner U.S. Cl. X.R. 9666.3 

